Cylinder adjustment for offset-printing machines



Dec. 17, 1929.

A. J. GRAF ET AL CYLINDER ADJUSTMENT FOR OFFS ET PRINTING MACHINES Filed Nov. 29, 1927 INVENTORS' nee iv, rare ALBERT J. GRAB, 0F WES'IFIELD, AND WILLIAM E. ECKHARD, OJF DUNELLEN, NEW JERSEY, ASSIGNOBS T9 R. HOE do CO. 1166., OF NEW YORK, N. Y., A CORPORATION GE NEW YORK Application filed November 29, 1927. Serial No. 236,399.

. This invention relates to certain-improve- .ments in printing machines.

In certain classes or types of printing machines, such as magazine and transfer or offo'set presses, the distance between centers of the form cylinder and impression cylinders is relatively fixed, and this is also true of oilset presses. In the printing operation if the cylinders get out of this predetermined relation they have to be adjusted to effect the proper printing relation. In offset machines the printing is effected by a form cylinder onto a transfer or blanket cylinder, the im pression being produced on the sheet by this cylinder and a cooperating impression cylinder. To obtain good printing 1n this type of press, it is necessary that the distance between the centers of the form cylinder and the ofiset cylinder and the ofi'set cylinder and the impression cylinderbe the same on both sides of the press, and that the distance from the center of the offset cylinder to the centers or" the form and impression cylinders be the same. a

This adjustment is a delicateone, and it is the especial object of the present L lli/611M011 provide a suitable measuring device by which a required adjusting movement may be quickly and accurately made, either with two or so more cylinders.

lit is a further object of the invention to provide an adjustable measuring device, and

. one that is readily removable and replaceable in the mechanism.

With these and other objects in view, the invention consists in certain novel parts, ar 'rangements and combinations which will be described in connection with the accompany ing drawings and the novel features pointed 2 out in the claims hereunto appended.

in the drawings,--

.tion provides means other relations and is not to be limited to a three cylinder machine of the offset type.

In the machine shown, however, there is a plate or form cylinder 1, a transfer or oflset cylinder 2, and an impression cylinder 3. These cylinders are preferably arranged, as

shown, with the form cylinder 1 and the transfer cylinder 2 arranged in vertical alignment, and the impression cylinder 3 in horizontal alignment with the ofiset cylinder.. In constructions embodying the invention, however, where used with an offset press, the distance between the centers of the offset cylinder and the form and impression cylinders will be the same as shown. In offset machines, tripping mechanism is provided for tripping the offset cylinder on and off impression, but this mechanism and the inkingmechanism for the form cylinder have not been shown, as unnecessary for an understanding of the invention.

in the operation of these machines, the cylinder must be in correct printing relation, and means are provided for eitecting a relative adjustment of the cylinders. This adjustment is a delicate one and has to be made with great accuracy, and the present invenfor rapidly, and accurately determining the required movement.

The means for eflectmg the adjusting movements of the cylinders may be somewhat varied. As shown, the c linders are mounted in suitable framing i, tli e bearings 5 for the cylinder 3 being stationary. The bearings for the ofiset cylinder and the form cylinder 85 are, however, movable. Thus the offset cylinder 2 is mounted in eccentric bushings 6, "which are adjustable by the rod 7 having right and left hand threads, by means of the adjusting unit 8. Similarly, the form cylinder 1 is adjustable in eccentric bushings 9 Figure 1 is a side view of a part of a print-/ bymeans of a threaded rod 10 and adjusting ing machine showing the invention;

Figure 2 is a plan view, partly in section, 5 of part of the machine shown 111 Figure 1, and idigure 3 shows the improved measuring device, as positioned when not in use.

Referring to these drawings, the machine chosen to illustrate the invention is a rotary i ottset press, but the invention is useful in units 11, 12. Thus the form cylinder be adjusted relativel and the latter cylin pression cylinder.

The means for effecting a rapid and accurate determination of the required adjusting movement may be somewhat varied, but will include a measuring device which may 100' may to the offset cylinder, er relatively to the imin limits,

"form of a rod 13 having at one end means by which it may be lengthened or shortened withas a micrometer gauge 14. This rod is set to the correct distance between the cylinders when in printing relation, so that by associating the rod with the center of one cylinder and bringing the rod into operatlve relation with the center of the other cylinder the required adjustment is readily and accurately determined.

The rod may be set to the required length in various ways. Preferably, the rod is removable from the cylinder, and where this is so the rod may be provided with a head 15 by which it maybe hung on a stud 16 secured to the frame of the machine. A second stud 17 is mounted in the side frame and the distance between the center of stud 16 and the surface of stud 17 is made equal to the distance between the centers of the cylinders when in printing relation. I The rod may be associated with the cylinder with which it is to be used in various ways. As shown, the cylinders 1 and 2 are provided with studs 18 concentric with the centers of the cylinders, these studs being formed by reducing the end'of a hub 19 on a plate20 secured to the bushings by bolts 21.

These studs 18 are arranged to receive the head 15 of the rod. Preferably, the rod and hub are formed separately, and the end of the rod is fitted into a socket 22 formed on the head 15.

With this construction the rod may be used with two cylinders as 1 and 2, or, where the press is an offset press, by simply turning the head 15 about the stud 18 the rod may be brought into engagement with the impression cylinder 3.

It will be seen that with the construction described a simple device has been provided for accurately determining the required adjustment of the cylinders. In use the rod is placed on the stud 18 of the cylinder 2 in line with the center of the cylinder 1. If the latter requires adjustment, this is effected by the adjusting nuts 11, 12, the cylinder being moved until its stud 18 engages the end of the rod. These two cylinders are now in correct printing relation. If now adjustment of the impression cylinder and the offset cylinder is required, the rod is turned to the position shown in full lines in Figure 1, and the cylinder 2 adjusted by the nut 8. It will be understood, of course, in the particular machine shown that the stud 18 on the offset cylinder is the siz: f the stud 16 on the frame,

and the studs 18 of the cylinders 1 and 3 are the size of the stud 17 on the frame.

WVhile the invention has been shown and described in its preferred form, it will be understood that the details of the measuring device may be varied, as may its association with the cylinders, and that the device may be used in other relations than with a three cylinder offset press without departing from the invention.

\Vhat is claimed is:

1. Ina printing machine, the combination of a form cylinder, a transfer cylinder and an impressioncylinder arranged with one of the cylinders located between the other two, and means for adjusting the cylinders relatively to each other, and a measuring device pivotally associated with the intermediate cylinder and movable about the center of the intermediate cylinder into measuring relation with the other cylinders for accurately determining the required adjusting movement of the cylinders.

2. In a printing machine, the combination of a form cylinder, a transfer cylinder and an impression cylinder arranged with the centers of the form cylinder and impression cylinder being equidistant from the center of the transfer cylinder when in printing relation, means for adjusting the cylinders relatively to each other, and a measuring device of a predetermined length pivotally associated with the transfer cylinder and movable about the center of the transfer cylinder for determining accurately the required adjusting movement of the cylinders.

3. In a printing machine, the combination of a form cylinder, a cooperating cylinder,

means for relatively adjusting the cylinders, a measuring rod having a head and a center stud on one of the cylinders for receiving the head and around which the rod may be swung, and a stud on the other cylinder for engaging the end of the rod as the rod is swung around the center stud for determining the adjustment of the cylinders.

4. In a printing machine, the combination of a form cylinder, a transfer cylinder and an impression cylinder, means for relatively adjusting the cylinders, and a measuring rod centrally associated with the transfer cylinder and rotatable around the transfer cylinder into operative relation with the form and impression cylinders for determining the In a printing machine, the combination v Ill 

